[ClusterLabs] Placing resource based on least load on a node

[Bernd]

Hi,

I'd like to run a certain bunch of cronjobs from time to time on the 
cluster node (four node cluster) that has the lowest load of all four 
nodes.

The parameters wanted for this system yet to build are

* automatic placement on one of the four nodes (i.e., that with the 
lowest load)

* in case a node fails, automatically removed from the cluster

* it must only exist a single entity of the cronjob entity running

so this really screams for pacemakter being used as foundation.

However, I'm not sure how to implement the "put onto node with least 
load" part. I was thinking to use Node Attributes for that, but I didn't 
find any solution "out of the box" for this. Furthermore, as load is a 
highly volatile value, how can one make sure that all cronjobs are run 
to the end without being moved to a node that possibly meanwhile got a 
lower load than the one executing the jobs?

Thanks,

Bernd